It was "the whack heard around the world." In January 1994, figure skater Nancy Kerrigan was clubbed in the knee during practice before the U.S. Women's Championships in Detroit — and the perpetrator was a hitman hired by the ex-husband of her rival, Tonya Harding. The shocking sports scandal is the subject of the new movie "I, Tonya." But here's the dramatic backstory between the two skaters that you didn't see:

Team USA swept the medals at the World Figure Skating Championships — the first time a single country had done so. Kristi Yamaguchi took gold, while Kerrigan won bronze and Harding got silver. Yamaguchi retired from the sport after that win, and many believed Kerrigan would be the next face of the sport.

Kerrigan was the darling of figure skating.

Harding was an impressive skater with unmatched athleticism — she was the first woman to attempt and land a triple axel. But Kerrigan was the darling of ice skating, racking up endorsements as the face of companies like Campbell's Soup and Revlon. Harding, meanwhile, had no endorsements or sponsorships after the '92 championships.

"She was a great skater and I was a great skater but she was treated like this queen," Harding says of Kerrigan in the documentary The Price of Gold.

Though both women came from blue-collar backgrounds, they were pitted against each other as opposites in the lead-up to the 1994 Olympics.

"You feel bad for her, to not have that stable home," Kerrigan told Sports Illustrated of Harding. "I am so lucky. It wasn't easy. I remember counting quarters and my parents counting money to buy groceries. But I lived in one place with two parents and it was stable. I had grandparents two houses away ... It's not like I was a princess. I happened to have good posture so I looked the part, I guess."

Harding says she was sleeping when the attack happened.

Kerrigan was coming off the ice after practice in Detroit when she was hit in the right knee by a man wielding a police baton. The attacker escaped, and the aftermath was caught on tape, with Kerrigan famously yelling out in pain, "Why? Why? Why? Why me?"

"I was sleeping when I found out what had happened," Harding said in The Price of Gold. "My coach woke me up and told me. I had a practice later on. I was scared to death, being out on that ice because nobody was caught."

It was days before Harding was implicated in the attack.

Local journalist Ann Schatz received an anonymous letter implicating Harding, her ex-husband Jeff Gillooly, and Harding's bodyguards in the attack on Kerrigan. "I'm thinking, this could be the start of something really crazy," Schatz says in The Price of Gold, "because this says they hatched the plan." Schatz called Harding, who agreed to be interviewed about it.

"I can't believe it. Why does someone want to discredit me? I just don't understand," Harding told Schatz. In the documentary, Harding says that after the interview, she asked Gillooly, "What did you do?" and that he responded by hitting her.

The letter was eventually turned over to FBI agents who discovered the woman who'd written the letter had learned about the attack from the father of one of Harding's bodyguards.

Gillooly told authorities Harding was in on planning the attack from the beginning.

Harding's ex told authorities that she called the Tony Kent Arena, where Kerrigan practiced in Michigan, to find out her schedule to help coordinate an attack. Harding denied his accusation when asked about it by the FBI. Gillooly even gave the FBI a scrap piece of paper with the name of the arena jotted down, saying Harding had written it. The FBI tested the handwriting and determined that some of the writing was Harding's but that other portions were Gillooly's.

Harding eventually admitted to delaying telling authorities about the assault.

In her first public comments about the attack, Harding said during a press conference, "I had no part in the planned assault on Nancy Kerrigan. I am responsible, however, for failing to report things I learned about the assault when I returned home from nationals."

The attack was meant to take Kerrigan out of competition.

It was reported that Harding's ex contacted Harding's bodyguard Eckardt to plan to attack. The bodyguard reportedly paid hit man Shane Stant $6,500 to whack Kerrigan and take her out of competition. Kerrigan's doctor told The New York Times, "He was clearly trying to debilitate her."

A Bleacher Report interview with Standt 20 years after the attack details:

A man named Shawn Eckardt called and said it would involve slicing the skater's Achilles tendon. Stant said no. He wouldn't cut anybody. They settled on injuring the person enough so she could not skate.

But Kerrigan recovered in time to compete in the 1994 Olympics against Harding.

The attack left Kerrigan injured for the Championships in Detroit, where Harding won first place. But by the time the Olympics took place in February, Kerrigan was able to compete and took home a silver medal.

Harding sued to remain on the Olympic team.

The U.S. Olympic Committee considered not allowing Harding to compete while the attack on Kerrigan was investigated. But Harding filed suit to block the impending hearing on her eligibility. That suit also demanded $20 million in damages, according to the Los Angeles Times. An agreement was reached, and Harding participated in the Games in Norway, where she placed eighth.

Harding was eventually stripped of her titles.

Six months after the Kerrigan attack, the U.S. Figure Skating Association stripped Harding of her 1994 national championship title and banned her from the organization for life because it was determined she knew about the attack.

"By a preponderance of the evidence, the five members of the panel concluded that she had prior knowledge and was involved prior to the incident," hearing panel chairman William Hybl told The Washington Post. "This is based on civil standards, not criminal standards."

An attorney for Harding, however, said, "She categorically denies the statements of Jeff Gillooly and others relied upon by the hearing panel that she had any prior knowledge of or participated in the assault on Nancy Kerrigan." And Harding maintains that she didn't know about the attack before it happened.

Kerrigan says she never got a direct apology from Harding.

In a 2017 interview, Kerrigan said, "We were at an event four years after I was attacked but we didn't really speak to each other so it was very awkward and strange." When the interviewer asks if she ever got an apology from Harding, Kerrigan responds, "Not a direct ... does it matter at this point?"

In a 2009 year interview, Harding told Oprah Winfrey, "If she'd let me, I'd love to give her a hug, you know, tell her how proud I am of her, being able to go forward with her life."